USB control circuit with automatic route-switching function

Abstract

The present invention discloses a universal serial bus (USB) control circuit, and more particularly, a USB control circuit with an automatic route-switching function. The USB control circuit comprises: a plurality of USB pads, connecting a plurality of USB devices; a plurality of USB transceivers, each connected to a corresponding USB pad; at least one USB controller, each connected to at least one corresponding USB transceivers, so as to control and drive the USB devices connected to the corresponding USB pads by using the corresponding USB transceivers; a plurality of port routing controllers, each connected to a corresponding USB transceiver; at least one enhanced USB transceivers, each connected to each of the USB pads and each of the port routing controllers; an enhanced USB controller, connected to each of the enhanced USB transceivers, so as to control and drive the enhanced USB devices connected to the corresponding USB pads by using the corresponding enhanced USB transceivers; and an enhanced device routing controller, connected to each of the port routing controllers, so as to automatically switch a USB pad that connects enhanced USB devices to the enhanced USB transceivers to be controlled by the enhanced USB controller.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention generally relates to a universal serial bus (to be abbreviated as USB hereinafter) control circuit, and more particularly, to a USB control circuit with an automatic route-switching function. The USB control circuit employs an enhanced device routing controller to operate in coordination with a plurality of port routing controllers and switching devices such that the port connected with enhanced USB devices is automatically switched to the enhanced USB transceivers to be controlled by the enhanced USB host controller.2. Description of the Prior ArtWith the rapid development in the information industry, people have increasing needs for a higher operation speed as well as a higher data transmission rate of information products. Universal Serial Bus (USB) technology according to the conventional USB standard (USB 1.1) has become insufficient in many aspects.The advantages of the USB standard include compatibility...

AI Technical Summary

Benefits of technology

It is another object of the present invention to provide a USB control circuit with an automatic route-switching function, where the number of enhanced USB transceivers is less than the number of USB pads so that the chip area is reduced and the fabrication cost is lowered.

Problems solved by technology

Universal Serial Bus (USB) technology according to the conventional USB standard (USB 1.1) has become insufficient in many aspects.

The conventional USB standard 1.1 has been applied in variety of computer peripheral application designs, but no one has heretofore thought to use it as an interface for an image processing system.

This is primarily because the conventional USB standard is much slower than the PCI or ISA buses.

Accordingly, USB 1.1 is not believed to be fast enough to support the data flow requirements of an image processing system.

Even though there is no such limit in another specification, the open host controller interface (OHCI), however, in practical cases, only three USB ports can be controlled.

The chip size of a generally utilized configuration with 6 USB ports may dramatically increase due to the enhanced USB transceiver is applied at every USB pads, and this will result in increasing fabrication cost.

Furthermore, the above configuration may lead to a considerable waste of resources since there is little chance for all the USB pads to be connected with enhanced USB devices.

This will limit the enhanced USB devices to be connected to some specific USB pads.

Therefore, if it is not confirmed whether each of the USB pads is connected to an enhanced USB transceivers such that some enhanced USB devices are connected to the pads that are not connected to the enhanced USB transceivers, and the enhanced USB devices will not function as they are designed to.

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